Environment & Climate Change

A bighead carp at the Shedd Aquarium in Chicago.

Asian carp have been making their way up the Mississippi River system for years after escaping from fish farms and wastewater treatment ponds in the southern U.S.They’re knocking on the door of the Great Lakes, and a number of people are concerned about what could happen if carp become established in the region.In this five-part series, we’ll take a look at what officials are trying to do to keep the fish out, what might happen if carp get in, and why some people want to turn carp into a business opportunity.

Hunt for Asian Carp resumes near Lake Michigan

Michigan Public | By The Associated Press

Published July 7, 2012 at 10:00 AM EDT

Juvenile silver carp, seen here, can grow up to weigh 100 pounds.

TRAVERSE CITY, Mich. (AP) - Authorities plan another intensive search for Asian carp next week after repeatedly detecting DNA from the invasive fish in Chicago's Lake Calumet.

Officials said Friday that genetic material from silver carp was found in samples taken in May and June. Policy requires stepped-up efforts to find the fish whenever their DNA turns up during three consecutive rounds of sampling in the same area.

Lake Calumet is on Chicago's South Side. A live Asian carp was caught there in 2010 - the only one found beyond an electric barrier meant to keep them out of the Great Lakes.

Crews will use nets and electrofishing in their search from Tuesday through Friday. Among the nets will be a new type designed to prevent fish from moving in and out of the lake.